Short-term adverse effects from and discontinuation of antiretroviral post-exposure prophylaxis.

OBJECTIVE: To evaluate short-term toxicity from and discontinuation of antiretroviral combination prophylaxis in HIV-exposed individuals in Italy. DESIGN: Longitudinal, open study conducted by prospective collection of data in the National Registry of PEP. SETTING: All the Italian centres dedicated to HIV related care and licensed by the Ministry of Health to dispense antiretroviral drugs. STUDY POPULATION: Health care workers and other persons consenting to be treated with post exposure prophylaxis (PEP) after exposures to HIV. RESULTS: Until October, 2000, 207 individuals receiving two nucleoside reverse transcriptase inhibitors (NRTIs), and 354 receiving two NRTIs plus a protease inhibitor (PI) were enrolled. More individuals experienced side-effects in the 3-drug group (53% and 62%, respectively; OR 0.68, (95% CI 0.48-0.98), p < 0.03). However, the proportion of individuals discontinuing prophylaxis because of side-effects did not differ significantly between the 2 groups (21% and 25% respectively; OR 0.82 (95% CI 0.53-1.26); p=0.4). The 43 individuals in the 2 NRTI group discontinued PEP after a mean of 10.4 days of treatment (median 8, range 1-27), similarly to the 88 discontinuations observed in the 3-drug group (mean duration 10.5 days, median 7.5, range 1-26). Type and incidence of specific adverse effects were similar to those reported in the literature. CONCLUSION: Our study indicates that the difference in the proportion of individuals developing side effects and discontinuing PEP is not significant. The rate of discontinuation because of protease inhibitor side-effects does not justify per se the initial use of a less potent PEP regimen. We suggest initiating PEP with a three-drug regimen and discontinuing the protease inhibitor in the case of adverse effects.